1. Field of the Invention
The present invention relates to a microcomputer logic development system. More particularly, the present invention is concerned with a system for developing the logic to be implemented in a built-in microcomputer that is used while being incorporated in an electronic control unit.
2. Description of the Related Art
The control of electronically controlled equipment, for example, the control of an engine by an electronic control unit (ECU), must be adjusted year by year in order to comply with regulations, including emission regulations or to improve the performance of the ECU along with improvement in the performance of a microcomputer. At present, new logic is developed prior to the improvement in the performance of the existing ECU. This preceding logic often targets the new generation of microcomputers expected to enjoy improved performance. Moreover, a new-generation microcomputer enjoying improved performance is selected based on the performance required to implement the preceding logic. However, an ECU in which a new-generation microcomputer enjoying improved performance is unavailable in practice. The preceding logic is therefore often developed using the logic implemented in an existing microcomputer as a base.
However, when an ECU having an existing microcomputer incorporated therein is used to develop the preceding logic, problems described below arise.
(1) The throughput of a CPU included in the microcomputer is insufficient.
(2) The storage capacity of a memory included in the microcomputer is small.
(3) The number of peripheral resources is too small.
(4) It takes much time to develop and manufacture a new-generation ECU.
Due to the above problems, development of a new-generation microcomputer is delayed. This hinders development of new electronically controlled equipment to be controlled by an ECU in which the new-generation microcomputer is incorporated.
A built-in microcomputer that is incorporated in an existing electronic control unit has the performance of a CPU and the capability of the peripheral equipment is selected based on the specifications optimal for an existing system to minimize the cost of the electronic control unit. Moreover, as the CPU and microcomputer peripheral resources are encased in one package, the capabilities of the CPU and peripheral resources cannot be modified independently of one another unless the microcomputer is modified. Moreover, for the development of logic to be implemented in the built-in microcomputer, a CPU whose throughput is large enough to implement the preceding logic must be provided, and the same assortment of microcomputer peripheral resources as the one to be included in a preceding system must be provided. Moreover, every time a new microcomputer is developed, an ECU must be manufactured in line with the microcomputer.